Field of the Invention
The present invention relates to a dehumidifier for a vehicle lamp, and more particularly, to a dehumidifier a vehicle lamp that continuously removes moisture formed in the lamp using an absorbent and a thermoelement.
Description of the Related Art
Generally, moisture formed within a head lamp mounted on a vehicle is caused by a difference between internal and external temperatures of a lens. For example when the head lamp is turned on or the internal temperature of the head lamp increases due to engine heat, the air temperature within the head lamp increases, and contains a larger amount of moisture. In particular, exposure to a cold fluid such as a natural fluid (e.g., rain, snow, ice) or an artificial fluid (e.g., car wash fluid or water) directly cools down the lens and, the temperature of the interior surface of the lens is reduced below the dew point. Accordingly, the moisture condenses on the lens and moisture formed on the lens degrades optical efficiency, and reduces the lifetime of the lens.
Therefore, technology for removing moisture formed on the lamp has been developed. For example, some exemplary techniques used to remove moisture formed on the lamp include forming a vent that passes through the interior and exterior of the lamp. The vent hole allows for a smooth air flow within the lamp. Accordingly, the moisture formed on the lamp is rapidly removed. However, when the lamp has a complex internal shape, the dehumidification effect may be degraded since the air flow within the lamp is not evenly distributed even through the vent is formed. In particular, the vent may become clogged with foreign matters thereby significantly degrading the dehumidification effect.
Another example of the technology is to install an absorbent in a lamp. The method of installing an absorbent has an improved dehumidification effect compared with the method of forming a vent. However, the recycle time required to dry the absorbent by the internal heat of the lamp increases with time. Thus, the dehumidification effect is degraded with time. In some instances, the absorbent may expel moisture contained therein, thereby accelerating the formation of moisture.
The above information disclosed in this section is intended merely to aid in the understanding of the background of the invention, and therefore may contain information that does not form the related art that is already known to those of ordinary skilled in the art.